Loons by Stan Tekiela

Author:Stan Tekiela
Language: eng
Format: epub
ISBN: 9781647552107
Publisher: Adventure Publications
Published: 2021-11-14T16:00:00+00:00

Submerging like a submarine

Loons are able to submerge gradually without diving headfirst like ducks. They can control their specific gravity by compressing their feathers and expelling air from their specialized air sacs and their lungs until their body weight is the same as the water. Because air is expelled, the oxygen they need does not come from air in the lungs but rather from oxyhemoglobin and oxymyoglobin stored in the blood and muscles. These are the substances responsible for the dark meat tissue in most birds.

Unlike ducks, which pop up to the surface like corks, loons can surface slowly or with just their heads showing above water. When loon parents need to hold fish to feed their tiny chicks, they surface at the height of the chicks and pass the food at the chicks’ level.

Loons also surface stealthily, with just the top of their heads and nostrils showing, to take a breath and head back underwater again. Silent partial surfacing can lead even keen-eyed observers to believe the birds are staying underwater much longer than is apparent.

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